py-libp2p/libp2p/stream_muxer/mplex/utils.py
2019-08-03 17:50:14 +08:00

59 lines
1.2 KiB
Python

import asyncio
import struct
from .constants import HEADER_TAGS
def encode_uvarint(number):
"""Pack `number` into varint bytes"""
buf = b""
while True:
towrite = number & 0x7F
number >>= 7
if number:
buf += bytes((towrite | 0x80,))
else:
buf += bytes((towrite,))
break
return buf
def decode_uvarint(buff, index):
shift = 0
result = 0
while True:
i = buff[index]
result |= (i & 0x7F) << shift
shift += 7
if not i & 0x80:
break
index += 1
return result, index + 1
async def decode_uvarint_from_stream(reader, timeout):
shift = 0
result = 0
while True:
byte = await asyncio.wait_for(reader.read(1), timeout=timeout)
i = struct.unpack(">H", b"\x00" + byte)[0]
result |= (i & 0x7F) << shift
shift += 7
if not i & 0x80:
break
return result
def get_flag(initiator, action):
"""
get header flag based on action for mplex
:param action: action type in str
:return: int flag
"""
if initiator or HEADER_TAGS[action] == 0:
return HEADER_TAGS[action]
return HEADER_TAGS[action] - 1